Glass perforating



Aug. 8, 1939.

W. A. MAHER GLAS S PERFORAT ING Fi led March 12, 1938 2'She ets-Sheet1 WILLIAM A. MAHER INVENTOR BY ATT RNEY Aug. 8, 1939. w. A. MAHER GLASS PnRFoRATIim Filed March 12, 1938 2 Sheets-Sheet 2 m m Jun WILLIAM A. MAI/ER lNVENTOR ATT RNEY Patented Aug. 8, 1939 UNiTED STAB GLASS PERFORATING Application March 12, 1938, Serial No. 195,626

21 Claims.

The invention herein disclosed relates to the art of perforating glass or material of this same general nature.

Special objects of the invention are to effect 51;? the formation of openings in glass or the like,

5; are set forth in the following specification, illustrated in the accompanying drawings and broadly covered in the claims annexed.

The drawings accompanying and forming part of the following specification illustrate one desirable commercial embodiment of the invention, but such disclosure is not necessarilyby way'of limitation, as structure may be modified and changed to suit special requirements, all within the true intent and scope of the invention as 5, hereinafter defined and broadly claimed.

Fig. 1 is a front elevation of the present machine, parts broken away and shown in section to disclose the valve for enabling return of sand from the collecting chamber to the sand holding 30 pressure tank.

Fig. 2 is a side elevation with parts at the bottom broken and in section to illustrate the injection of the sand into the air stream.

Fig. 3 is a broken part sectional enlarged view,

35? of the cooperating blast and receiving nozzles and associated parts.

Fig. i is a further enlarged broken sectional detail illustrating the nozzles separated but with the work in position over the gate or blast defin- 4' ing nozzle. 1

Fig. 5 is a face view showing a circular blank located in position over the gate or mask defining the final cutting area of the blast nozzle.

Figs. 6 and 7 are sectional details showing the blank as first perforated from one side and then as reversed and cut through with a finishing blast from the opposite side.

In the machine illustrated, compressed air from a suitable source is carried by piping W, to a nozzle H, in an ejector head !2, Fig. 2, which is connected at one side in the bottom of a sand containing pressure tank i3, and has extending from the end of it a sand blast hose l4, leading to a blast nozzle 15.

The blastnozzle I5 is located within a chamher [6, directly above the tank I3, and discharges forwardly into a blast confining apertured nozzle plate or mask ll, Figs. 3 and 4. The latter is shown as seated in a flange or bushing i8, secured on the outside of a forward vertical wall l9, of chamber 16, in exposed relation adapted to have the work placed directly thereover.

The work is indicated at 20, as a circular disc, to serve, when perforated, as a radio dial and this is located and supported in proper register over the aperture plate by a guide made up of two opposed partly circular segments 2|, sumciently separated at opposite sides, such as at 22, Fig. 5, to admit fingers of the operator for placing and removing the work.

To protect the glass, the mask or nozzle plate is faced with rubber similarly perforated as indicated at 23. This serves both as a cushion and as a further means for accurately defining and restricting the area to be perforated.

Directly opposite and in register With the perforating nozzle is a blast receiving nozzle 24, faced with rubber at 25, for gripping engagement with the oppositeface of the glass. This receiving nozzle is carried by a sleeve 26, sliding in a supporting head 21, toward and away from the first nozzle.

Movement is imparted to the second nozzle by rocker arms 28, having pin and slot connections 29, with opposite sides of the sleeve 26, these rocker arms being fixed on rock shaft 30, which has at one end a lever 3!, connected by link 32, with a foot treadle 33, pivoted at 36. This treadle is shown as counterbalanced at 35, to rock the treadle upwardly, thus to effect the retraction or withdrawal of 'the receiving nozzle and to normally hold the parts in such relation as illustrated in Fig. 2.

A yielding lost motion coupling is interposed in the operating connections from the treadle to enable first the closing of the nozzle against the work and then after the Work is securely gripped between the nozzles, an uncovering of the blast nozzle to initiate the cutting operation. This coupling is shown in the form of a block 36, having pin and slot connection 31, with the end of lever 3i, and slidingly engaged on the treadle link 32, between a fixed stop shoulder 38, at the bottom and a sliding washer 39, acted on by spring 433, and forming a yielding abutment at the top. The fixed shoulder 38, upon the rising of the treadle raises lever 3|, to rock the shaft 30 left-handedly from the position shown in Fig. 3, to that indicated in Fig. 2, to positively retract '2 tion in front of nozzle l5.

- suction blower 64, Fig. 1.

the collecting nozzle, whereas on depression of the treadle, the top abutment 39 may yield as indicated in Fig. 3, to permit limited further downward movement of the treadle. This additional movement is utilized to effect the uncovering of the blast nozzle.

In the machine shown, a rubber shutter 4|, is carried by a lever 42, pivoted at 43, and counterweighted at 44, Fig. 1, to drop down into posi- The outer end of lever 42 is shown connected by link 45, with a rock lever 46, pivoted at the back of the machine 41, Fig. 2, and having a slotted flange 48, at its forward end loosely embracing the link 32, in position to be engaged by an abutment 49, on said link after the treadle has completed the nozzle closing, work engaging movement.

The sliding nozzle is shown as retained against rotary movement by having a pin 50, Fig. 3, operating in a guide slot 5!, in the supporting head 27. The retractive movement of this nozzle is shown as governed by a stop collar 52, adjustably secured on the forward exposed portion of the sleeve 26, by set screw 53.

The sand and. cuttings driven into the mouth of the movable nozzle are carried through a loop of flexible hose 54, into the front portion of the collecting chamber l6. Thus with continuous operation of the machine, the sand in the pressure tank will eventually all be withdrawn and be delivered by blast nozzle l5, and the cooperating collection nozzle 24,into the collection chamber 16. Return of this sand to the pressure vessel is provided for in the present disclosure by a passage 55, Fig. 1, in the conical wall 56, forming the bottom of the collection chamber and the top of the sand holder, said passage being normally sealed by an upwardly closing rubber faced conical valve 51, which will be held closed during operation of the machine by pressure within the tank and which when the pressure is off may be lifted to its seat by chain 58, connected with the inner end of a lever handle 59, pivotally supported at 60.

For charging the machine in the first instance and for renewing the sand as and when required,

and to aid withdrawal of the sand and cuttings by the second-nozzle, suction is applied to the top of the cutting and collection chamber I6, through piping indicated at 63, connected with a A bafile is indicated at 65, Fig. 2, over the blast nozzle and back of the shutter to prevent sand rebounding from the shutter passing off through the exhaust pipe. Screened suction inlets are indicated at 66, Fig. 1,. for admitting some air into the upper front portion of the collection chamber above the nozzle return pipe 54, to pick up and carry away dust particles received from such nozzle.

The nozzles are suitably lined or tipped to withstand the flow of cutting sand therethrough. In

the illustration, the blast nozzle is shown as having a hardened tip or lining, 61, of suitable material, such as tungsten carbide. The mask plate 1, which in effect constitutes a companion part of the blast nozzle may be of similar material and the receiving nozzle may have an insert, lining or tip 68, of the same or equally suitable material.

Operation The cutting material or sand may be entered in the machine by way of the collecting chamber at the top upon removal of the door 6|. With valve 51 open as in Fig. 1, such sand will then pass directly down into the tank or holder I3. The normal or inoperative position of the parts is as indicated in Figs. 1 and 2, with the shutter 4i, dropped down in front of blast nozzle I5, so that the compressed air may be turned on as at the valve 69, at any time. At the time of turning on pressure, the sand return valve 51, may be lifted to its closed position, it being thereafter retained in said position by pressure within the sand vessel.

The nozzles separate sufficiently to enable the work such as a dial or disc 20, to he slipped into the guide or holder 2|, in properly registered position over the stencil mask or front nozzle plate l1. Then when the operator presses the treadle 33, the second nozzle 24 will be thrust into close fitting engagement with the outer face of the work, immediately following which through takeup of lost motion at 49, 48, Fig. 2, lever 46, will be tripped to effect the lifting of shutter 41, 4|, from its covering position over the discharge nozzle !5. As this nozzle is uncovered, the sand, blast strikes the area of the work exposed and defined by the stencil mask IT. The direct blast of sand so concentrated quickly cuts through the circumscribed area forming a tapering opening on the order of that represented at 10, Fig. 6. The cutting through is indicated by a difference in sound resulting from passage of the blast on through into the receiving nozzle or knowledge of the short time required may be quickly gained by trial operation of the machine. With the cutting through from one side, the treadle or pedal is released, which action first effects dropping of the shutter to cut off the blast and then separation of the nozzles. The work may then be reversed in the holder and the short operation repeated to cut the hole through from thev opposite side, as represented at H, Fig. '7. These two cuts in ordinary operations produce a clean edge opening through the glass which tapers slightly inward from opposite faces, so that any high points are at the center of the glass rather than at the surfaces, so that there will be no tendency to form surface chips or cracks if the glass should be fitted tightly over a supporting shaft or the like.

Ordinarily, suction is maintained at the separating chamber to carry off dust and to keep exposed parts of the apparatus free of dust or grit, during the entire operation of the machine. The work is kept at the outside of the machine, where it can be readily handled and the cutting and blast conducting operations are entirely confined. Operations therefore are quick, clean and safe. If desired, the blank feeding and reversing operations may be effected automatically. Instead of reversing the work, it is contemplated that the nozzles or the action of the nozzles may be reversed, that is, one nozzle be used to cut through from one side, with the other nozzle serving as an offtake and then the second nozzle be used to cut through from the opposite side and the first nozzle operate as an oiftake, such nozzles then each being controlled by a shutter or other suitable means for effecting control of the cutting blast.

Different thicknesses of glass may be handled in the same machine, this being allowed for by the operating connections yielding at spring 40, after the nozzles have closed on the work. Openings of different sizes and shapes may be formed tended periods of use.

by use of appropriate stencil masks. Many changes are possible within the scope of the invention, so the terms employed are to be construed in a broad descriptive sense rather than by way of limitation, except possibly for limitations such as may be implied by state of the prior art.

While different pressure connections and controls may be employed, one practical method-is to have an on and off valve at 59, for governing the blast creating flow and a valve 12 with control valve 13, by which a regulated degree of pressure may be admitted through a top connection is, into the holder i3, above the sand therein. When the machine is shut down, accumulated pressure may be released from the pressure tank by opening an exhaust valve indicated at 15.

By making the nozzle defining members H and 68, Fig. 4 of tungsten carbide, the cutting action of the sand is resisted and the nozzle apertures thereby maintained the same size over long ex- The facings of rubber which are laminated to the tungsten carbide nozzles act to cuslnon the glass, enabling the nozzles to be quickly and firmly closed on the glass. These rubber layers exclude all sand and dust from the covered, masked portions of the glass.

What is claimed is:

1. In a glass perforating device, registering stencil masks exposed for placement of the glass between them, foreffecting relative separation and approach of said masks and wholly enclosed means for directing a cutting blast into one stencil and for carrying away the cutting-through blast from the other mask and means interconnected with said means for effecting relative separation and approach of the masks for automatically stopping said cutting blast before separation and for starting said blast after the approach of said stencil masks.

2. In a glass perforating device, registering stencil masks exposed for placement of the glass between them, means for eifecting relative sepadration and approach of said masks and wholly enclosed means for directing a cutting blast into one stencil mask and for carrying away the cutting-through blast from the other mask, including opposed nozzles, one a blast nozzle discharging into one stencil mask and the other a blast receiving nozzle back of the other stencil mask, said means for effecting relative separation and approach of the masks including means support ing one of said nozzles movable in a fixed path toward and away from; the other nozzle with mechanism for so shifting said movably supported nozzle, a chamber enclosing said blast nozzle and a return conduit from said blast receiving nozzle to said chamber.

3. In a glass perforating device, registering stencil masks exposed for placement of the glass between them. means for effecting relative separation and approach of said masks and wholly enclosed means for directing a cutting blast into one stencil mask and for carrying away the cutting-through blast from the other mask, including opposed nozzles, one a blast nozzle discharg ing into one stencil mask and the other a blast receiving nozzle back of the other stencil mask, said means for eifecting relative separation and approach of the masks including means supporting one of said nozzles movable in a fixed path toward and away from the other nozzle with mechanism for so shifting said movably supported nozzle, a chamber enclosing said blast nozzle, a return conduit from said blast receiving nozzle to said chamber and suction creating means connected with said chamber.

l. In a glass perforating device, a sand holder, a collecting chamber above said holder, valve means for enabling return of sand from said collecting chamber to said holder, a blast nozzle in said chamber, blast conducting pressure connections from said sand holder to said blast nozzle, 9. stencil mask in line with said blast nozzle and exposed at one face to the outside of the chamber, a cooperative registering stencil mask at the outside of the chamber, means for effecting relative separation of said masks to receive the glass between them andfor approaching the same to close them on the inserted glass and interconnected means for automatically effecting stopping and starting of the blast respectively when the stencil masks are separated and when they are closed.

5. In a glass perforating device, a sand holder, a collecting chamber above said holder, valve means for enabling returnof sand from said collecting chamber to said holder, a blast nozzle in said. chamber, blast conducting pressure connections from said sand holder to said blast nozzle, a stencil mask in line with said blast nozzle and exposed at one face to the outside of the chamber, a cooperative registering stencil mask at the outside of the chamber, means for effecting relative separation of said masks to receive the glass between them and for approaching the same to close them on the inserted glass, means for effecting stopping and starting of the blast respectively when the stencil masks are separated and when they are closed, including a blast cutoff shutter movable into position between said blast nozzle and the stencil mask in line with the same and connected for operation in definitely timed relation by said means for effecting relative separation and approach of said stencil masks.

6. In a glass perforating device, a sand holder, a collecting chamber above said holder, valve means for enabling return of sand from said collecting chamber to said holder, a blast nozzle in said chamber, blast conducting pressure connections from said sand holder to said blast nozzle, a stencil mask in line with said blast nozzle and exposed at one face to the outside of the chamher. a cooperative registering stencil mask at the outside of the chamber, means for effecting relative separation of said masks to receive the glass between them and for approaching the same to close them on the inserted glass, including a conduit having a movable portion carrying one of said masks and means for shifting said movable conduit portion toward and away from the other mask, interconnected means for effecting stopping and starting of the blast respectively when the stencil masks are separated and when they are closed and means for applying suction to said collecting chamber, said movable conduit section being connected with said collecting chamber.

'7. In a glass perforating device, registering stencil masks exposed for placement of the glass between them, means for effecting relative separation and approach of said masks, wholly enclosed means for directing a cutting blast into one stencil mask and for carrying away the cutting-through blast from the other mask and a holder for definitely positioning glass blanks in proper relation between said registering stencil masks.

8. In a glass perforating device, registering stencil masks exposed for placement of the glass between them, means for effecting relative separation and approach of said masks and wholly enclosed means for directing a cutting blast into one stencil mask and for carrying away the cutting-through blast from the other mask and correspondingly stenciled non-cutting glass gripping facings on the opposed faces of said registering masks.

9. In a glass perforating device, cooperating, registering stencil masks, means for supporting one in stationary relation, a sleeve slidable toward and away from said first mask and supporting the other mask in position to cooperate with the first, a blast nozzle directed at one of said masks, means for effecting movement of said sleeve toward and away from said first mask and blast controlling means associated with said nozzle for'starting the blast after predetermined approaching movement and for stopping the blast before separating movement of said mask carrying sleeve.

10. In a glass perforating device, cooperating, registering stencil masks, means for supporting one in stationary relation, a sleeve slidable to ward and away from said first mask and supporting the other mask in position to cooperate with the first, a blast nozzle directed at one of said masks, means for effecting movement of said sleeve toward and away from said first mask and blast controlling means associated with said nozzle for starting the blast after predetermined approaching movement and for stopping the blast before separating movement of said mask carrying sleeve and a blast receiving conduit connected with said sleeve.

11. In a glass perforating device, cooperating opposed relatively separable nozzles of tungsten carbide having correspondingly perforated cushioning layers of rubber over the opposing faces of r the same for yieldingly gripping glass therebetween and means for effecting relative separating and approaching movements of said nozzles to enable placing of glass between said nozzles and the gripping of such glass between said perforated cushioning layers.

a glass perforating blast nozzle within said enclosure and directed at said stencil opening, an olftake conduit outside said enclosure, a mask at the end of said ofitake conduit and having an opening to register with the stencil opening of said first mask and means for enabling relative separation and approach of said olftake mask and said enclosure mask sufficient to permit the placing of a glass blank at the outside of said enclosure between saidenclosure mask and said offtake conduit mask and engagement of said masks with opposite faces of a blank so placed.

13. In a glass perforating device, the combination of a blast confining enclosure, a mask forming part of said enclosure and having a stencil opening forming an outlet from said enclosure, a giass perforating blast nozzle within said enclosure and directed at said stencil opening, an ofitake conduit outside said enclosure, a mask at the end of said offtake conduit and having an opening to register with the stencil opening of said first mask, said offtake conduit including a movable end portion carrying said second mask and means for shifting said movable end portion of said offtake conduit toward and away from said enclosure mask.

14. In a glass perforating device, the combination of a blast confining enclosure, a mask forming part of said enclosure and having a stencil opening forming an outlet from said enclosure, a glass perforating blast nozzle within said enclosure and directed at said stencil opening, an offtake conduit outside said enclosure, a mask at the end of said oiftake conduit and having an opening to register with the stencil opening of said first mask, means for enabling relative separation and approach of said oiftake mask and said enclosure mask sufficient to permit the placing of a glass blank at the outside of said enclosure between said enclosure mask and said offtake conduit mask and engagement of said masks with opposite faces of a blank so placed, a tubular hub on the wall of said enclosure positioned to receive the blast from said glass perforating nozzle, said enclosure mask being carried by said hub and guide means carried by said hub in front of said mask for locating a blank in definite position thereover.

15. In a glass perforating device, the combination of a blast confining enclosure, a mask forming part of said enclosure and having a stencil opening, a glass perforating blast nozzle within said enclosure and directed at said stencil opening, an ofitake conduit outside said enclosure, a mask at the end of said offtake conduit and having an opening to register with the stencil opening of said first mask, means for effecting relative separation and approach of said ofitake conduit and enclosure to enable placing of a glass blank between said masks and engagement of said masks with opposite faces of a blank so placed, a shutter movable to cover and uncover the blast nozzle and connections between said means and said shutter for shifting the shutter to cover the blast nozzle before the relative separation described and for uncovering said blast nozzle after engagement of the masks with opposite faces of a blank.

16. In a glass perforating device, the combination of a blast confining enclosure, a mask forming part of said enclosure and having a stencil opening forming an outlet from said enclosure, a glass perforating blast nozzle within said. enclosure and directed at said stencil opening, an offtake conduit outside said enclosure, a mask at the end of said offtake conduit and having an opening to register with the stencil opening of said first mask, means for enabling relative separation and approach of said offtake mask and said enclosure mask sufiicient to permit the placing of a glass blank at the outside of said enclosure between said enclosure mask and said offtake conduit mask and engagement of said masks with opposite faces of a blank so placed, exhaust means connected to apply suction to said enclosure and said offtake conduit being connected to discharge into said enclosure and whereby said oiftake conduit is subjected to the suction applied to said enclosure.

17. In a glass perforating device, the combination of a blast confining enclosure, a mask forming part of said enclosure and having a stencil opening forming an outlet from. said enclosure, a glass perforating blast nozzle within said enclosure and directed at said stencil opening, an oiftake conduit outside said enclosure, a mask at the end of said ofitake conduit and having an opening to register with the stencil opening of said first mask, means for enabling relative separation and approach of said offtake mask and said enclosure mask sufficient to permit the placing of a glass blank at the outside of said enclosure between said enclosure mask and said offtake conduit mask and engagement of said masks With opposite faces of a blank so placed, exhaust means connected to apply suction to said enclosure and said offtake conduit being connected to discharge into said enclosure and whereby said offtake conduit is subjected to the suction applied to said enclosure, said enclosure having an atmospheric inlet adjacent the point of discharge of said offtake conduit thereinto.

18. In a glass perforating device, the combination of a blast confining enclosure, a mask forming part of said enclosure and having astencil opening forming an outlet from said enclosure, a glass perforating blast nozzle within said enclosure and directed at said stencil opening, an offtake conduit outside said enclosure, a mask at the end of said offtake conduit and having an opening to register with the stencil opening of said first mask, means for enabling relative separation and approach of said offtake mask and said enclosure mask sufficient to permit the placing of a glass blank at the outside of said enclosure between said enclosure mask and said offtake conduit mask and engagement of said masks with oppositefaces of a blank so placed, exhaust means connected to apply suction to said en closure and said offtake conduit being connected to discharge into said enclosure and whereby said offtake conduit is subjected to the suction applied to said enclosure, an abrasive holder connected to receive abrasive collected within said enclosure and controllable valve means regulatable to discharge collected abrasive from the enclosure into the abrasive holder and to seal the enclosure off from the abrasive holder.

19. In a glass perforating device, the combination of relatively separable sections of a flow conduit arranged one in continuation of the other, opposed stencil masks at the opposing ends of said relatively separable conduit sections, means for effecting the relative separation and approach of said conduit sections to enable the placing of a glass blank between the sections and the engagement of the same by the stencil masks at the ends of said separable sections, a glass perforating blast nozzle discharging into one conduit section and means for controlling the action of said glass perforating nozzle in time with the separating and approach of said conduit sections.

20. A glass perforating machine, comprising an abrasive holding pressure tank, a'blast enclosing chamber above said pressure tank, a pressure closed dump valve between said chamber and pressure tank for dumping collected abrasive in said chamber into said pressure tank when pressure in the latter is released, a substantially vertically disposed mask on an exterior wall of said chamber and having a stencil opening forming an outlet from said chamber, a substantially horizontally extending blast nozzle in said chamber and directed to said stencil opening, a pressure connection from said abrasive holding pressure tank to said blast nozzle, an offtake conduit including a movable section outside said chamber and movable in a generally horizontal direction toward and away from said stencil mask, a cooperating stencil mask at the end of said movable section, resilient facings on the opposed faces of said stencil masks, means for effecting movement of the movable section of the offtake conduit toward and away from the enclosure mask for effecting the gripping of an inserted blank between said mask facings and the release of a gripped blank after the same has been perforated by blast through the opposing masks.

21. In a glass perforating machine, the combination of opposed abrasive resisting stencil plates having matching openings of desired outline, rubber facings over the opposed faces of said stencil plates having corresponding openings, a blast nozzle positioned to direct a cutting blast into the stencil opening in one plate, a blast receiving conduit extending away from the other Stencil plate, means for eifecting relative separation and approach of said stencil plates to permit placing of the work between the same and the closure of said rubber facings against the interposed work and means for automatically controlling the cutting blast in accordance with the relative opening and closing movements of said stencil plates.

WILLIAM A. MAHER. 

